Yet another polymorph of α-synuclein: solid-state sequential assignments

Parkinson's disease is a neurological human proteinopathy, which is caused by the accumulation of protein aggregates of high molecular mass. alpha-Synuclein is a major component of these fibrillar, beta-sheet rich, insoluble assemblies and is deposited in the form of amyloids. Structural characterization of amyloids is possible by solid-state NMR, although no atomic-resolution structure is available as of today. alpha-Synuclein, as many other pathology-related fibril-forming proteins, can form a number of different polymorphs that are sometimes tricky to obtain in pure form. Here, we describe the chemical shifts and secondary structure analysis of a polymorph that also adopts mainly beta-sheet conformation, with a fibrillar core ranging from residues 38 to 94. In addition, residues 15-20 from the N-terminus found to be part of a rigid ordered beta-sheet. The chemical shifts differ substantially from the polymorph we previously assigned.